The present invention relates to locking mechanisms for closures and more particularly to door and boot locking mechanisms for motor vehicles.
A locking mechanism is known which includes a housing fixed to a vehicle the housing having a barrel rotatably mounted therein which is renderable into unlocked and locked modes respectively by insertion of a key into or withdrawal of the key from the barrel. In this mechanism the barrel, with the correct key inserted, locks and unlocks a door latch mechanism permanently connected thereto by rotation of the barrel in one direction or the other respectively. Rotation of the barrel, and hence unlocking of the door latch mechanism, is prevented with the barrel in the locked mode by a series of tumblers extending radially of the barrel into engagement with the fixed housing.
It is a disadvantage of this type of locking mechanism that the mechanism may be forced by forcible rotation of the barrel which will result either in breakage of the tumblers or rotation of both the housing and barrel with respect to the door; both of these eventualities enabling unauthorised unlocking of the door latch mechanism.
It is an object of the present invention to provide a locking mechanism in which forcible rotation of the barrel, when in the locked mode, will not unlock a door latch mechanism.